1. Field of the Invention
The present disclosure is related to auto-injection devices. More particularly, the present disclosure is related to a coupling for auto-injection devices for releasably securing an injection spring to a plunger rod.
2. Description of Related Art
Diseases such as AIDS, Hepatitis, and others, are increasing within the general population. The onset of these diseases has increased the desire to prevent inadvertent needle sticks during the use of syringe assemblies. Many prior art devices include self-retracting needles to mitigate inadvertent needle sticks.
Many life-threatening situations such as allergy induced anaphylactic shock, and exposure to chemical, radiological, and biological weapons can require the use of automatic injection devices. Also, many non-threatening conditions can be candidates for use of such automatic injection devices. However, the cost of the prior art automatic injection device can make such use by consumers cost prohibitive.
Typical automatic injection devices are syringe assemblies that allow the medically untrained user to automatically inject a medicine by manually trigging the automatic injection. Some prior automatic injection devices also incorporate self-retracting needles. Such automatic injection and retraction assemblies included a coupling that releasably couples an injection spring to a syringe plunger. Unfortunately, many prior couplings require tight manufacturing tolerances, which can increase the overall cost of the device.
Accordingly, there is a continuing need for auto-injection devices and couplings for such devices that overcome and/or mitigate one or more of the aforementioned and other deficiencies and deleterious effects of prior automatic injection devices.